5
Dual-boot questions (but not about Windows)
(feddit.uk)
From Wikipedia, the free encyclopedia
Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is typically packaged in a Linux distribution (or distro for short).
Distributions include the Linux kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy.
Community icon by Alpár-Etele Méder, licensed under CC BY 3.0
@smeg It sounds like the issue might be that you are running them on separate drives, as opposed to partitions. You may have two installations of Grub.
You might have to run update-grub on the older installation in order to re-detect everything because grub will detect the installations on other drives but the second one did not yet exist at the time it was installed on the first drive.
And, it all depends on which drive the computer is actually booting from. If you have two versions of grub, then the one that launches is the one that the computer boots up from. If that one hasn't detected what is on the other drive, then you won't see it.